1. Field of the Invention
The present invention relates to a multilayer ceramic electronic component to be embedded in a board and a printed circuit board having a multilayer ceramic electronic component embedded therein.
2. Description of the Related Art
As electronic circuits have become highly densified and highly integrated, a mounting space for passive elements mounted on a printed circuit board (PCB) has become insufficient, and in order to solve this problem, ongoing efforts have been made to implement components able to be installed within a board, i.e., embedded devices. In particular, various methods have been proposed for installing a multilayer ceramic electronic component used as a capacitive component within a board.
In one of a variety of methods of installing a multilayer ceramic electronic component within a board, the same dielectric material used for a multilayer ceramic electronic component is used as a material for a board and a copper wiring, or the like, is used as an electrode. Other methods for implementing a multilayer ceramic electronic component to be embedded in a board include a method of forming the multilayer ceramic electronic component to be embedded in the board by forming a polymer sheet having high-k dielectrics and a dielectric thin film within the board, a method of installing a multilayer ceramic electronic component within a board, and the like.
In general, a multilayer ceramic electronic component includes a plurality of dielectric layers made of a ceramic material, and internal electrodes interposed between the dielectric layers. By disposing such a multilayer ceramic electronic component within a board, an embedded multilayer ceramic electronic component having high capacitance may be implemented.
In order to manufacture a printed circuit board (PCB) including a multilayer ceramic electronic component embedded therein, a multilayer ceramic electronic component may be inserted into a core board, and via holes are required to be formed in an upper laminated plate and a lower laminated plate by using a laser in order to connect board wirings and external electrodes of the multilayer ceramic electronic component. Laser beam machining, however, considerably increases manufacturing costs of a PCB.
Meanwhile, since the multilayer ceramic electronic component needs to be embedded in the core portion of the board, a nickel/tin (Ni/Sn) plating layer does not need to be formed on the external electrode, unlike in the case of a general multilayer ceramic electronic component mounted on a surface of a board.
That is, since the external electrode of the multilayer ceramic electronic component to be the embedded in the board is electrically connected to a circuit in the board through a via formed of copper (Cu), instead of through a nickel/tin (Si/Sn) layer, a copper (Cu) layer needs to be formed on the external electrode.
Generally, since even the external electrode is formed of copper (Cu) as a main component but also includes glass, the glass component absorbs the laser during laser beam machining for forming the via in the board, and thus, it may be difficult to adjust a depth of the via.
For this reason, such a copper (Cu) plating layer has been separately formed on the external electrode of the multilayer ceramic electronic component to be embedded in the board.
However, due to the separate copper (Cu) plating layer, manufacturing costs may be increased, and due to the permeation of a plating solution, reliability may be deteriorated. Therefore, the above defects still need to be solved.